Extinct order of brachiopods (Brachiopoda), which have biconvex shells, a straight hinge line, and well-developed cardinal areas on both valves (see cardinal tooth). The pedicle opening notches into both valves and is not usually restricted by plates. The shells are usually impunctate. Orthida range from the Lower Cambrian to the Upper Permian, e.g. Orthis (Ordovician).
Orthida
- Canada–France–Hawaii Telescope
- Canadian
- Canadian Indians
- Canadian Journal of Statistics
- Canadian Space Agency
- canale
- canaliculus
- canalization((in evolutionary genetics))
- canalizing selection
- canal rays
- canals, Martian
- Canaries current
- canary
- Canberra distance
- cancel
- cancelbot
- cancellation
- cancellation laws
- cancellation negation
- Cancer
- cancer
- Cancer, Tropic of
- cancrinite
- candela
- candle power